Humidity-controlling apparatus.



J. M. LARSON.

HUMIDITY CONTROLLING APPARATUS.

APPLICATION FILED JAN. 11, I910.

1,1533%. PatentedSept. 14, 1915.

1 1 1w v A I I I 0:5, -1

JOHN M. LARSON, 0F CHICAGQ.

ILLINOIS, Assrsnon. r0 NATIONAL REGULATOR- COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 615 ILLINOIS.

HUMIDITY-CONTROLLING arrlmerusl I i To all whom it may concern:

Be itknown that I, JOHN M. LARSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Humidity-Controlling Apparatus, -of which the following is a full,-

clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

This invention relates to improvements in means for regulating the amount of moisture discharged into the air of a habitable room or space. I

In the accompanying drawings, inwhlch I have shown a practical application of my invention, there; is illustrated acombination and arrangement of-apparatus in the'use of rod 44Iwhich forms-a post supportingthe" which air is drawn into a ventilatingduct from a suitable place, as, for instance some point exterior to the building, and is first passed over or through a heatingapparatus,

the latter being controlled by a thermostat of some suitable type, placed in the ductat'a point beyond the heater soas to be affected by the warmed air. The air then passes along the duct andv is. finally delivered to the space which is to beheated and ventilated. At some convenient point, as in the duct, there is arranged suitable'means for delivering into the duct, when required, a quantity of Water vapor, which mingles with the air. Hygrostatic means, so located as to be in-. fluenced by the moisture in the air, measure the amount ofhumidity and control the action of the moisture-delivering means as required to maintain the 'airat thedesired humidity point:

' In the drawings, Figure 1 is a front view,

principally in elevation, of the hygrost'at or" humidlty-responsi've device which controls the moisture increasing means, with the cover or protecting cap removed; Fig; 2 is a front elevational View of the hygrostat with, a the cover'inplace; Fig. '3 -is across sectional View of the same, the'section being taken on the line 44 of Fig. 3; Fig. 4-is' a side eleva;

tional view'of the lower portion of thehygrostat with the cover removed. The hygrostat comprises a base member 34 which maybe secured to the Wall 35 of the room by means. of screws 36 and 37 Extending upward from the base member 34 is a pillar 38, the lower end of which is screw threaded and'scr'ewedinto a correspondingly] pecification of Letters Patent. P t s 1p 13' 19115.. Application filed January 11, 1910. Serial No. 537,504, f

the post 44. 'The resilient strip 46 has a .slight tendency to move the valve 45 away from the port 41. The hygrostatic element threaded'depression in the top of the member 34. Apassage 39 extends-upward through the base member and registers with a; I

passage 40 which extends through the pillar. 38 for a portion of its length and opens'at the seharge port 41 at the tip of a laterally pro]ect1ng nipple 42. A pipe leads to the;

passage 39 of the base member, the air which 4 hygrostatic element of the device and a valve actuated thereby. The valve 45 is hung, by means of a strip 46 of resilient metal, upon a block 47 which is secured upon comprises a strip of wood 48 cut so that the grain runs crosswise of the strip, and a strip of brass or other suitable metal 49 which ex .tends along one side of the wood strip 48. .85

Secured to the upper end of the strip '49 is a".

metal block 50 from which extends upwardv 4 a thin metallic strip. 51 by means of which" the hygrostatic element is supported or hung s in front of the valve- 45 from a' block 52' which is secured to and carried by the post},

44. Upon the lower end of the strip 49 is s secured a second metallic block 53.. The strlp 48 of wood is confined at its endsbetween the blocks 50 and 53, and any expansion of this strip lengthwise which is due to an increased v amount of moisture will, by the stripbeari ing u onf these end block, cause the metal-- strip- 9 to be flexed so thatits lower end moves toward the valve 41. The metal strlp does not absorb moisture and therefore is not 'increased'or decreased in length by changes I k i i iin-the amount of moisture in the surround a ing air. Itis. however, lengthenedor shortened by rise-and fall of temperature, but as thevwood strip 48 is likewise lengthened or shortened by temperature changes, littleqor 'nogflexin of the hygrostatic element asa I 'whole-resu ts mere'ly from a rise in tempera hygrostatic element is adjusted toward and away from the discharge port 41. Upon the lower end of the strip 49 is provided a rounded hump 58 which bears upon the valve; 45. 1

When the temperature of the surrounding air risestthemetal strip 49 and the wood Q strip 48 expand .or lengthen together. The

' jlengthening of these strips hasno effect upon the valve .41, as the rounded hump 58 =merely slidesdow fn along the back of the valve 45. The device is thus .seen to be not directly, afiected, so far as the regulation of the flow of air from the port 41 is con-' cerned, by temperature changes. Such changes indirectly afl'ectthe position of the valve, however, as will be pointed out. Changes in the-amount of humidity in the surrounding medium alter the position of the valve with respect to-its seat and thus vary the amount of air which is permitted to flow from the port 41, because the wood strip-'48expands when the amount of moisture increases,- while' the metal strip 49 does not expand.

- l In practical service. it is desired that the relative -humidity,' rather than the absolute humidity offthe atmosphere of the room or space, he maintained practically constant.

By relative humidity is meant the ratio .be-

. tween the total amount of humidity which air will carry without-precipitation at the temperature existing .inthe room and the: amount actually present, As iswell' undcrv stood, allfla fa. glven' temp rature Wi 'h air for any other reason to become too moist. 1 in suspens on a certain quantity of water vapor, but if the temperature be lowered,"

or if-the quantity of'moisture be increased,

the airnotable to" hold all of the vapor in suspension and precipitation begins to I conditionof. the air with respect to, the

, amountof moisture carriedthereby usuallygive .thel percentage fof the total amount; which'would be required to saturate the air at the'exis'ting temperature.

' The hygrostatic' element which I em ploy is capable of sogo'verning thevalve 45 asj'to -maiutarin"the relative zhumidity practically constant. .In order to efieet thisitmust be able to increase the *activity of the vaporizerwhe'n' the temperature-rises and to' decrease it'when theltempe'rature falls for the reason that the dew point rises with the tem-v ea perature. If such a "degree of humidity is 1 metal expands. tendst'o expand, but this tendency is not as to be maintained that the per cent. of satu-. ration is constant it is evident that a rise in temperature should be accompanied by an increase in the amount of moisture in the atmosphere.

It has been customary to employ in apparatus of this class, for the hygrostatic element, a strip of hygroscopic material such as ivood cut with the grain running crosswise, this strip being so employed as to thrust 'endwise against a lever or other means for transmitting its motion to a valve. Such a strip of wood, employed in this way, is, upon a rise in temperature, subjected to. two influences working against each other.

;The strip tends to lengthen because of the rise in temperature and it tends to shorten because of the fact that the air, being warmer, takes up a part of the moisture which was present in or upon the strip. On the other hand, if the temperature falls, the strip tends to shorten because of the change i in-temperature but tends also to lengthen because of the fact that the air, being cooler, is more ready to part with its moisture and a quantity is absorbed by the wood. These two opposing forces thus to a great extent interfere with the efliciency of such devices.

In my improved hygrostat, if the temperature of the surrounding medium be lowered the efi'ect upon the metal strip 49 will be to .shorten the same. The effect upon the wood strip 48 is to lengthen the same, because the Upon the temperature rising the strip of The wood strip likewise great as its tendency to contract due to the fact that the air now has an increased avidity for moisture and dries out the wood strip to a certain extent. The combined action of the metal strip and the wood strip are-now to open the valve, as would be the case were the air to become too dry.

' Ifthe-valve for the port 41 were carried directly by the hygrostatic element it would. not ,always seat properly ,as the angle between the axis of the port and the back of the metal strip 49 is not always the same.

Moreover, the hygrostat as a whole lengthens .Sand shortens under temperature changes. As this occurs the rounded hump 58 simply slides along the back of the valve without aflecting the latter in any way.

To protect the hygrostat and conceal the same a suitable cover or casing 59 is provided. this cover having a lug 61 at each of its ends by means of which it may be secured by suitable screws 62 or the like to the wall to which the hygrostat is secured. This cover is formed with a series of perforations 63 to permit the passage of air freely to the sensitive element. these openings being guarded by wire screens or the like 64: to prevent the insertion of pencils and the like by meddlesomepersons.

Having thus described my invention. what I claim as new, and desire to secure by Letters Patent. is:

1. The combination of a base. a pillar extending therefrom. said base and pillar hav ing a passage extending therethrough and, terminating in a port at the side of the pillar. a valve hung in front of said port and supported bysaidpillar, and a hygrostatic element consisting of a strip of metal and a strip of hygroscopic material arranged parallel with each other. said element being supported at one end from said pillar. the other end of said element bearing upon said valve and moving toward said port when said element is flexed and having movement transversely of said port, when elongated.

2. A hygrostathaving a port, a valve supported in front of said port, a hygrostatic element arranged in front of said valve and supported at one of its ends so as to be ca pable of swinging. and means for angular-1y adjusting said end and thereby regulating the position of the opposite end of the element with respect to said valve. v

3. The combination of a base. a pillar extending therefrom, said base and pillar having a passage extending therethrough and terminating in a port att-he side of the pillar, a. valve hung in front of said port, and a hygrostatic element consisting of astrip of metal and a strip of hygroscopic ma' terial arranged "parallel with each other, said element being supported at one end from said pillar, the other end of said elementbearing upon said valve and moving toward said portwhen said element is flexed and having movement transversely of said port when elongatedl. A hygrostat having a port, a valve supported in front of said port. a hygrostatic element arranged in front of said valve and supported at one of its ends so as to be capable of-swinging, and means for regulating the position of the opposite end of the element with respect to said valve, said hygrostat-ic element consisting of a hygroscopic element and a non-hygroscopic element. each having the same co-eflicient of expansion by 7 witnesses.

JOHX M. LARSON.- Witnesses:

CHAS. L. Hormxs, CHAS. G. Corn. 

